If you are trying to perform openstack operations through CLI did you source the openrc file which contains the auth_url and the credentials required to authenticate against keystone? If you don't have those environment variables set you will get this issue. Try souring an openrc file in the below format.

Create and source the OpenStack RC file

Alternatively, you can create the PROJECT-openrc.sh file from scratch, if for some reason you cannot download the file from the dashboard.

In a text editor, create a file named PROJECT-openrc.sh file and add the following authentication information: